We propose to develop further our present studies with scientists in Brazil on leishmaniasis, schistosomias, malaria and Chagas' disease. These are approached by a number of disciplines including immunology, molecular biology, biochemistry, pathology, entomology, malacology, epidemiology, and clinical medicine. Our long-term goal is to develop effective vaccines or to delineate other avenues to control these diseases. Studies on LEISHMANIASIS in Manaus, Belem, and Bahia include: the evaluation of a new diagnostic test we have developed using kinetoplast DNA hybridization for rapid identification of Leishmania species on a touch blot of cutaneous lesions; developing a rapid test for identifying Leishmania in lesions using species and subspecies specific monoclonal antibodies; obtaining purified species specific antigens with those antibodies to develop serologic and skin tests; evaluating the use of monoclonal antibodies to detect Leishmania in sandflies; and studying possible defects in the immune regulation of diffuse and mucocutaneous leishmaniasis. Studies on SCHISTOSOMIASIS in Bahia include: extending our previous studies on a factor produced by normal monocytes which enhances the killing of schistosomula by eosinophils, but which is not produced by cells from patients with schistosomiasis; evaluate the IgE-basophil system in these patients; produce human monoclonal antibodies to S. mansoni with peripheral lymphocytes from patients; analyze the S. mansoni antigens in kidney lesions with these antibodies, and, in Sergipe, evaluate the role of B. straminea in transmission of S. mansoni and analyze snail lectins that may play a part in the defense mechanisms of the snail. Studies on MALARIA in Manaus include: studies to determine the extent of the diversity of P. falciparum by surface immunofluorescence of infected rbc; developing a rapid diagnostic assay for the field using ELISA and monoclonal antibodies; applying methods of molecular biology to the rapid diagnosis of malaria and the cloning of enzymes which may be important in drug resistance, studying immunosuppression in patients with malaria and investigating the tropical splenomegaly syndrome. Studies on CHAGAS' disease are concerned with developing the model of chronic Chagasic myocarditis in dogs designed in part as a model to evaluate chemotherapy and the safety and efficacy of potential vaccine preparations of T. cruzi.